Within the U.S., the National Resources Defense Council ranks the top 5 sustainable cities as Seattle, WA, San Francisco, CA, Portland, OR, Oakland, CA, and San Jose, CA. The criteria for this ranking were as follows: Green Building, Standard of Living, Air Quality, Environmental Standards and Participation, Recycling, Transportation, Energy Production and Conservation, Green Space, and Water Quality.

In Europe, a study, developed by the Economist Intelligence Unit, called the European Green City Index, declared the top 5 sustainable cities to be: Copenhagen, Denmark, Stockholm, Sweden, Oslo, Norway, Vienna, Austria, and Amsterdam, The Netherlands. This index considered the following criteria: